1 /*
2 * Copyright (c) 2018, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
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23 */
24
25 #include "ci/ciInlineKlass.hpp"
26 #include "gc/shared/c1/modRefBarrierSetC1.hpp"
27 #include "utilities/macros.hpp"
28
29 #ifdef ASSERT
30 #define __ gen->lir(__FILE__, __LINE__)->
31 #else
32 #define __ gen->lir()->
33 #endif
34
35 void ModRefBarrierSetC1::store_at_resolved(LIRAccess& access, LIR_Opr value) {
36 DecoratorSet decorators = access.decorators();
37 bool is_array = (decorators & IS_ARRAY) != 0;
38 bool on_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
39
40 // Is this a flat, atomic access that might require gc barriers on oop fields?
41 ciInlineKlass* vk = access.vk();
42 if (vk != nullptr && vk->has_object_fields()) {
43 // Add pre-barriers for oop fields
44 for (int i = 0; i < vk->nof_nonstatic_fields(); i++) {
45 ciField* field = vk->nonstatic_field_at(i);
46 if (!field->type()->is_primitive_type()) {
47 int off = access.offset().opr().as_jint() + field->offset_in_bytes() - vk->payload_offset();
48 LIRAccess inner_access(access.gen(), decorators, access.base(), LIR_OprFact::intConst(off), field->type()->basic_type(), access.patch_emit_info(), access.access_emit_info());
49 pre_barrier(inner_access, resolve_address(inner_access, false),
50 LIR_OprFact::illegalOpr /* pre_val */, inner_access.patch_emit_info());
51 }
52 }
53 }
54
55 if (access.is_oop()) {
56 pre_barrier(access, access.resolved_addr(),
57 LIR_OprFact::illegalOpr /* pre_val */, access.patch_emit_info());
58 }
59
60 BarrierSetC1::store_at_resolved(access, value);
61
62 if (access.is_oop()) {
63 bool precise = is_array || on_anonymous;
64 LIR_Opr post_addr = precise ? access.resolved_addr() : access.base().opr();
65 post_barrier(access, post_addr, value);
66 }
67
68 if (vk != nullptr && vk->has_object_fields()) {
69 // Add post-barriers for oop fields
70 for (int i = 0; i < vk->nof_nonstatic_fields(); i++) {
71 ciField* field = vk->nonstatic_field_at(i);
72 if (!field->type()->is_primitive_type()) {
73 int inner_off = field->offset_in_bytes() - vk->payload_offset();
74 int off = access.offset().opr().as_jint() + inner_off;
75 LIRAccess inner_access(access.gen(), decorators, access.base(), LIR_OprFact::intConst(off), field->type()->basic_type(), access.patch_emit_info(), access.access_emit_info());
76
77 // Shift long value to extract the narrow oop field value and zero-extend
78 LIR_Opr field_val = access.gen()->new_register(T_LONG);
79 access.gen()->lir()->unsigned_shift_right(value,
80 LIR_OprFact::intConst(inner_off << LogBitsPerByte),
81 field_val, LIR_Opr::illegalOpr());
82 LIR_Opr mask = access.gen()->load_immediate((julong) max_juint, T_LONG);
83 access.gen()->lir()->logical_and(field_val, mask, field_val);
84 LIR_Opr oop_val = access.gen()->new_register(T_OBJECT);
85 access.gen()->lir()->move(field_val, oop_val);
86
87 assert(!is_array && !on_anonymous, "not suppported");
88 post_barrier(inner_access, access.base().opr(), oop_val);
89 }
90 }
91 }
92 }
93
94 LIR_Opr ModRefBarrierSetC1::atomic_cmpxchg_at_resolved(LIRAccess& access, LIRItem& cmp_value, LIRItem& new_value) {
95 if (access.is_oop()) {
96 pre_barrier(access, access.resolved_addr(),
97 LIR_OprFact::illegalOpr /* pre_val */, nullptr);
98 }
99
100 LIR_Opr result = BarrierSetC1::atomic_cmpxchg_at_resolved(access, cmp_value, new_value);
101
102 if (access.is_oop()) {
103 post_barrier(access, access.resolved_addr(), new_value.result());
104 }
105
106 return result;
107 }
108
109 LIR_Opr ModRefBarrierSetC1::atomic_xchg_at_resolved(LIRAccess& access, LIRItem& value) {
110 if (access.is_oop()) {
111 pre_barrier(access, access.resolved_addr(),
112 LIR_OprFact::illegalOpr /* pre_val */, nullptr);
113 }
114
115 LIR_Opr result = BarrierSetC1::atomic_xchg_at_resolved(access, value);
116
117 if (access.is_oop()) {
118 post_barrier(access, access.resolved_addr(), value.result());
119 }
120
121 return result;
122 }
123
124 // This overrides the default to resolve the address into a register,
125 // assuming it will be used by a write barrier anyway.
126 LIR_Opr ModRefBarrierSetC1::resolve_address(LIRAccess& access, bool resolve_in_register) {
127 DecoratorSet decorators = access.decorators();
128 bool needs_patching = (decorators & C1_NEEDS_PATCHING) != 0;
129 bool is_write = (decorators & ACCESS_WRITE) != 0;
130 bool is_array = (decorators & IS_ARRAY) != 0;
131 bool on_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
132 bool precise = is_array || on_anonymous;
133 resolve_in_register |= !needs_patching && is_write && access.is_oop() && precise;
134 return BarrierSetC1::resolve_address(access, resolve_in_register);
135 }